1. Field of the Invention
This invention relates to underwater lighting systems, and more particularly for lighting systems used in swimming pools, spas and the like for both safety and aesthetic purposes.
2. Background of the Invention
In-ground swimming pools and spas are often installed with lights, typically in a horizontal row a short distance below the waterline. The underwater lighting has a pleasing visual effect and permits safe swimming during nighttime.
More recently, colored lights have been used, with programmable controllers for turning selected lights on and off, effectively producing an underwater light show for the pool's users. In a typical application, an underwater light fixture (also called a luminaire) includes an array of light-emitting diodes (LEDs) coupled to a microprocessor. A specific color is obtained by powering different LEDs in combinations of primary colors (e.g. LEDs in red, green and blue). A light fixture is turned on or off in accordance with a programmed sequence by alternately supplying and interrupting power to the light fixture. For example, as shown in FIG. 1, a light fixture 110 has an array of LEDs 100 controlled by a microprocessor 115. Each light fixture has a power relay 116 for interrupting power from a power supply 118.
It is desirable to provide a programmable lighting system where the lights may turn on or off, change color and brightness, and/or appear to move, according to programmed sequences (including user-defined sequences) that do not depend on power interruption.